Thisfiledescribesvariousproblemsthathavebeenencounteredincompiling,installingandrunningGNUEmacs.*`PidxxxkilledduetotextmodificationorpageI/Oerror'On HP/UX, you can get that error when the Emacs executable is on an NFSfile system. HP/UX responds this way if it tries to swap in a page anddoes not get a response from the server within a timeout whose defaultvalue is just ten seconds.If this happens to you, extend the timeout period.* `expand-file-name'failstoworkonanybutthemachineyoudumpedEmacson.OnUltrix,ifyouuseanyofthefunctionswhichlookupinformationinthepasswddatabasebeforedumpingEmacs(say,byusingexpand-file-nameinsite-init.el),thenthosefunctionswillnotworkinthedumpedEmacsonanyhostbuttheoneEmacswasdumpedon.Thesolution?Don't use expand-file-name in site-init.el, or inanything it loads. Yuck - some solution.I'mnotsurewhythishappens;ifyoucanfindoutexactlywhatisgoingon,andperhapsfindafixoraworkaround,pleaseletusknow.PerhapstheYPfunctionscachesomeinformation,thecacheisincludedinthedumpedEmacs,andistheninaccurateonanyotherhost.*OnsomevariantsofSVR4,EmacsdoesnotworkatallwithX.TrydefiningBROKEN_FIONREADinyourconfig.hfile.Ifthissolvestheproblem,pleasesendabugreporttotellusthisisneeded;besuretosayexactlywhattypeofmachineandsystemyouareusing.*Linkingsaysthatthefunctionsinsqueandremqueareundefined.ChangeoldXMenu/Makefilebyaddinginsque.otothevariableOBJS.*EmacsfailstounderstandmostInternethostnames,eventhoughthenamesworkproperlywithotherprogramsonthesamesystem.ThistypicallyhappensonSunsandothersystemsthatusesharedlibraries.Thecauseisthatthesitehasinstalledaversionofthesharedlibrarywhichusesanameserver--buthasnotinstalledasimilarversionoftheunsharedlibrarywhichEmacsuses.Theresultisthatmostprograms,usingthesharedlibrary,workwiththenameserver,butEmacsdoesnot.Thefixistoinstallanunsharedlibrarythatcorrespondstowhatyouinstalledinthesharedlibrary,andthenrelinkEmacs.*OnaSunrunningSunOS4.1.1,yougetthiserrormessagefromGNUld:/lib/libc.a(_Q_sub.o): Undefined symbol __Q_get_rp_rd referenced from text segment TheproblemisintheSunsharedClibrary,notinGNUld.ThesolutionistoinstallPatch-ID#100267-03fromSun.*Selfdocumentationmessagesaregarbled.Thismeansthatthefile`etc/DOC-...' doesn'tproperlycorrespondwiththeEmacsexecutable.RedumpingEmacsandtheninstallingthecorrespondingpairoffilesshouldfixtheproblem.*TroubleusingptysonAIX.PeopleofteninstalltheptydevicesonAIXincorrectly.Use`smitpty' to reinstall them properly.* Shell mode on HP/UX gives the message, "`tty`: Ambiguous".christos@theory.tn.cornell.edu says:The problem is that in your .cshrc you have something that tries toexecute `tty`. If you are not running the shell on a real tty then tty will print "not a tty". Csh expects one word in some places, but tty is giving it back 3.The solution is to add a pair of quotes around `tty` to make it a singleword: if (`tty` == "/dev/console") should be changed to:if ("`tty`" == "/dev/console") Even better, move things that set up terminal sections out of .cshrcand into .login.* Using X Windows, control-shift-leftbutton makes Emacs hang.Use the shell command `xset bc'tomaketheoldXMenupackagework.*EmacsrunningunderXWindowsdoesnothandlemouseclicks.*`emacs-geometry80x20' finds a file named `80x20'.Onecauseofsuchproblemsishaving(setqterm-file-prefixnil)inyour.emacsfile.AnothercauseisabadvalueofEMACSLOADPATHintheenvironment.*Emacsstartsinadirectoryotherthantheonethatiscurrentintheshell.IfthePWDenvironmentvariableexists,Emacsusesthisvariableastheinitialworkingdirectory.Someshellsautomaticallyupdatethisvariable,whileothershellsfailtodoso.Ifyouusetwosuchshellsincombination,thevariablecanendupwrong.ThisconfusesEmacs.Thesolutionistoputsomethinginthestart-upfilefortheshellthatdoesnotupdatePWD,togetridofthatenvironmentvariable.Forexample,incsh,use`unsetenvPWD'.* Emacs gets error message from linker on Sun.If the error message says that a symbol such as `f68881_used'or`ffpa_used' or `start_float'isundefined,thisprobablyindicatesthatyouhavecompiledsomelibraries,suchastheXlibraries,withafloatingpointoptionotherthanthedefault.It's not terribly hard to make this work with small changes incrt0.c together with linking with Fcrt1.o, Wcrt1.o or Mcrt1.o.However, the easiest approach is to build Xlib with the defaultfloating point option: -fsoft.* Emacs fails to get default settings from X Windows server.The X library in X11R4 has a bug; it interchanges the 2nd and 3rdarguments to XGetDefaults. Define the macro XBACKWARDS in config.h totell Emacs to compensate for this.I don'tbelievethereisanywayEmacscandetermineforitselfwhetherthisproblemispresentonagivensystem.*KeyboardinputgetsconfusedafterabeepwhenusingaDECserverasaconcentrator.ThisproblemseemstobeamatterofconfiguringtheDECservertouse7bitcharactersratherthan8bitcharacters.*M-xshellpersistentlyreports"Process shell exited abnormally with code 1".ThishappenedonSunsasaresultofwhatissaidtobeabuginSunosversion4.0.x.Theonlyfixwastorebootthemachine.*Programsrunningunderterminalemulatordonotrecognize`emacs' terminal type.The cause of this is a shell startup file that sets the TERMCAPenvironment variable. The terminal emulator uses that variable toprovide the information on the special terminal type that Emacsemulates.Rewrite your shell startup file so that it does not change TERMCAPin such a case. You could use the following conditional which setsit only if it is undefined. if ( ! ${?TERMCAP} ) setenv TERMCAP ~/my-termcap-fileOr you could set TERMCAP only when you set TERM--which should nothappen in a non-login shell.* X Windows doesn'tworkifDISPLAYusesahostname.PeoplehavereportedkernelbugsincertainsystemsthatcauseEmacsnottoworkwithXWindowsifDISPLAYissetusingahostname.ButtheproblemdoesnotoccurifDISPLAYissetto`unix:0.0'. I thinkthe bug has to do with SIGIO or FIONREAD.You may be able to compensate for the bug by doing (set-input-mode nil nil).However, that has the disadvantage of turning off interrupts, so thatyou are unable to quit out of a Lisp program by typing C-g.The easy way to do this is to put (setq x-sigio-bug t)in your site-init.el file.* Problem with remote X server on Suns.On a Sun, running Emacs on one machine with the X server on anothermay not work if you have used the unshared system libraries. Thisis because the unshared libraries fail to use YP for host name lookup.As a result, the host name you specify may not be recognized.* Watch out for .emacs files and EMACSLOADPATH environment varsThese control the actions of Emacs.~/.emacs is your Emacs init file.EMACSLOADPATH overrides which directories the function"load" will search.If you observe strange problems, check for these and get ridof them, then try again.* Shell mode ignores interrupts on Apollo DomainYou may find that M-x shell prints the following message: Warning: no access to tty; thus no job control in this shell...This can happen if there are not enough ptys on your system.Here is how to make more of them. % cd /dev % ls pty* # shows how many pty'syouhave.Ihad8,namedpty0topty7)%/etc/crpty 8#createseightnewpty's* Fatal signal in the command temacs -l loadup inc dumpThis command is the final stage of building Emacs. It is run by theMakefile in the src subdirectory, or by build.com on VMS.It has been known to get fatal errors due to insufficient swappingspace available on the machine.On 68000's,ithasalsohappenedbecauseofbugsinthesubroutine`alloca'. Verify that `alloca'worksright,evenforlargeblocks(manypages).*test-distribsaysthatthedistributionhasbeenclobbered*or,temacsprints"Command key out of range 0-127"*or,temacsrunsanddumpsxemacs,butxemacstotallyfailstowork.*or,temacsgetserrorsdumpingxemacsThiscanbebecausethe.elcfileshavebeengarbled.Donotbefooledbythefactthatmostofa.elcfileistext:thesearebinaryfilesandcancontainall256bytevalues.Inparticular`shar' cannot be used for transmitting GNU Emacs.It typically truncates "lines". What appear to be "lines" ina binary file can of course be of any length. Even once `shar'itselfismadetoworkcorrectly,`sh' discards null characterswhen unpacking the shell archive.I have also seen character \177 changed into \377. I do not knowwhat transfer means caused this problem. Various networkfile transfer programs are suspected of clobbering the high bit.If you have a copy of Emacs that has been damaged in itsnonprinting characters, you can fix them: 1) Record the names of all the .elc files. 2) Delete all the .elc files. 3) Recompile alloc.c with a value of PURESIZE twice as large. You might as well save the old alloc.o. 4) Remake xemacs. It should work now. 5) Running xemacs, do Meta-x byte-compile-file repeatedly to recreate all the .elc files that used to exist. You may need to increase the value of the variable max-lisp-eval-depth to succeed in running the compiler interpreted on certain .el files. 400 was sufficient as of last report. 6) Reinstall the old alloc.o (undoing changes to alloc.c if any) and remake temacs. 7) Remake xemacs. It should work now, with valid .elc files.* temacs prints "Pure Lisp storage exhausted"This means that the Lisp code loaded from the .elc and .elfiles during temacs -l loadup inc dump took up morespace than was allocated.This could be caused by 1) adding code to the preloaded Lisp files 2) adding more preloaded files in loadup.el 3) having a site-init.el or site-load.el which loads files. Note that ANY site-init.el or site-load.el is nonstandard; if you have received Emacs from some other site and it contains a site-init.el or site-load.el file, consider deleting that file. 4) getting the wrong .el or .elc files (not from the directory you expected). 5) deleting some .elc files that are supposed to exist. This would cause the source files (.el files) to be loaded instead. They take up more room, so you lose. 6) a bug in the Emacs distribution which underestimates the space required.If the need for more space is legitimate, change the definitionof PURESIZE in puresize.h.But in some of the cases listed above, this problem is a consequenceof something else that is wrong. Be sure to check and fix the realproblem.* Changes made to .el files do not take effect.You may have forgotten to recompile them into .elc files.Then the old .elc files will be loaded, and your changeswill not be seen. To fix this, do M-x byte-recompile-directoryand specify the directory that contains the Lisp files.Emacs should print a warning when loading a .elc file which is olderthan the corresponding .el file.* The dumped Emacs (xemacs) crashes when run, trying to write pure data.Two causes have been seen for such problems.1) On a system where getpagesize is not a system call, it is definedas a macro. If the definition (in both unexec.c and malloc.c) is wrong,it can cause problems like this. You might be able to find the correctvalue in the man page for a.out (5).2) Some systems allocate variables declared static among theinitialized variables. Emacs makes all initialized variables in mostof its files pure after dumping, but the variables declared static andnot initialized are not supposed to be pure. On these systems youmay need to add "#define static" to the m- or the s- file.* Compilation errors on VMS.You will get warnings when compiling on VMS because there arevariable names longer than 32 (or whatever it is) characters.This is not an error. Ignore it.VAX C does not support #if defined(foo). Uses of this constructwere removed, but some may have crept back in. They must be rewritten.There is a bug in the C compiler which fails to sign extend charactersin conditional expressions. The bug is: char c = -1, d = 1; int i; i = d ? c : d;The result is i == 255; the fix is to typecast the char in theconditional expression as an (int). Known occurrences of suchconstructs in Emacs have been fixed.* rmail gets error getting new mailrmail gets new mail from /usr/spool/mail/$USER using a programcalled `movemail'.Thisprograminterlockswith/bin/mail usingtheprotocoldefinedby/bin/mail.Therearetwodifferentprotocolsingeneraluse.Oneofthemusesthe`flock' system call. The other involves creating a lock file;`movemail'mustbeabletowritein/usr/spool/mail in order to dothis.Youcontrolwhichoneisusedbydefining,ornotdefining,themacroMAIL_USE_FLOCKinconfig.horthem-ors-fileitincludes.IFYOUDON'T USE THE FORM OF INTERLOCKING THAT IS NORMAL ON YOURSYSTEM, YOU CAN LOSE MAIL!If your system uses the lock file protocol, and fascist restrictionsprevent ordinary users from writing the lock files in /usr/spool/mail,you may need to make `movemail'setgidtoasuitablegroupsuchas`mail'. You can use these commands (as root): chgrp mail movemail chmod 2755 movemail* Emacs won'tworkwithX-windowsifthevalueofDISPLAYisHOSTNAME:0.*GNUscan't make contact with the specified host for nntp.Some people have found that Emacs was unable to connect to the localhost by name, as in DISPLAY=prep:0 if you are running on prep, butcould handle DISPLAY=unix:0. Here is what tale@rpi.edu said: Seems as though gethostbyname was bombing somewhere along the way. Well, we had just upgrade from SunOS 3.5 (which X11 was built under) to SunOS 4.0.1. Any new X applications which tried to be built with the pre OS-upgrade libraries had the same problems which Emacs was having. Missing /etc/resolv.conf for a little while (when one of the libraries was built?) also might have had a hand in it. The result of all of this (with some speculation) was that we rebuilt X and then rebuilt Emacs with the new libraries. Works as it should now. Hoorah.If you have already installed the name resolver in the file libresolv.a,then you need to compile Emacs to use that library. The easiest way todo this is to add to config.h a definition of LIBS_SYSTEM, LIBS_MACHINEor LIB_STANDARD which uses -lresolv. Watch out! If you redefine a macrothat is already in use in your configuration to supply some other libraries,be careful not to lose the others.Thus, you could start by adding this to config.h:#define LIBS_SYSTEM -lresolvThen if this gives you an error for redefining a macro, and you see thatthe s- file defines LIBS_SYSTEM as -lfoo -lbar, you could change config.hagain to say this:#define LIBS_SYSTEM -lresolv -lfoo -lbar* Emacs spontaneously displays "I-search: " at the bottom of the screen.This means that Control-S/Control-Q "flow control" is being used.C-s/C-q flow control is bad for Emacs editors because it takes awayC-s and C-q as user commands. Since editors do not output long streamsof text without user commands, there is no need for a user-issuable"stop output" command in an editor; therefore, a properly designedflow control mechanism would transmit all possible input characterswithout interference. Designing such a mechanism is easy, for a personwith at least half a brain.There are three possible reasons why flow control could be taking place: 1) Terminal has not been told to disable flow control 2) Insufficient padding for the terminal in use 3) Some sort of terminal concentrator or line switch is responsibleFirst of all, many terminals have a set-up mode which controlswhether they generate flow control characters. This must beset to "no flow control" in order for Emacs to work. Sometimesthere is an escape sequence that the computer can send to turnflow control off and on. If so, perhaps the termcap `ti'stringshouldturnflowcontroloff,andthe`te' string should turn it on.Once the terminal has been told "no flow control", you may find itneeds more padding. The amount of padding Emacs sends is controlledby the termcap entry for the terminal in use, and by the output baudrate as known by the kernel. The shell command `stty'willprintyouroutputbaudrate;`stty' with suitable arguments will set it ifit is wrong. Setting to a higher speed causes increased padding. Ifthe results are wrong for the correct speed, there is probably aproblem in the termcap entry. You must speak to a local Unix wizardto fix this. Perhaps you are just using the wrong terminal type.For terminals that lack a "no flow control" mode, sometimes justgiving lots of padding will prevent actual generation of flow controlcodes. You might as well try it.If you are really unlucky, your terminal is connected to the computerthrough a concentrator which sends flow control to the computer, or itinsists on sending flow control itself no matter how much padding yougive it. You are screwed! You should replace the terminal orconcentrator with a properly designed one. In the mean time,some drastic measures can make Emacs semi-work.One drastic measure to ignore C-s and C-q, while sending enoughpadding that the terminal will not really lose any output. To makesuch an adjustment, you need only invoke the functionenable-flow-control-on with a list of terminal types in your own.emacs file. As arguments, give it the names of one or more terminaltypes you use which require flow control adjustments.Here'sanexample:(enable-flow-control-on"vt200""vt300""vt101""vt131")AnevenmoredrasticmeasureistomakeEmacsuseflowcontrol.Todothis,evaluatetheLispexpression(set-input-modenilt).EmacswilltheninterpretC-sandC-qasflowcontrolcommands.(Moreprecisely,itwillallowthekerneltodosoasitusuallydoes.)YouwilllosetheabilitytousethemforEmacscommands.Also,asaconsequenceofusingCBREAKmode,theterminal's Meta-key, if any,will not work, and C-g will be liable to cause a loss of output whichwill produce garbage on the screen. (These problems apply to 4.2BSD;they may not happen in 4.3 or VMS, and I don'tknowwhatwouldhappeninsysV.)Youcanusekeyboard-translate-table,asshownabove,tomaptwootherinputcharacters(suchasC-^andC-\)intoC-sandC-q,sothatyoucanstillsearchandquote.IhavenointentionofeverredesigningtheEmacscommandsetfortheassumptionthatterminalsuseC-s/C-qflowcontrol.Thisflowcontroltechniqueisabaddesign,andterminalsthatneeditarebadmerchandiseandshouldnotbepurchased.IfyoucangetsomeuseoutofGNUEmacsoninferiorterminals,Iamglad,butIwillnotmakeEmacsworseforproperlydesignedsystemsforthesakeofinferiorsystems.*Control-SandControl-Qcommandsareignoredcompletely.Forsomereason,yoursystemisusingbrain-damagedC-s/C-qflowcontroldespiteEmacs's attempts to turn it off. Perhaps yourterminal is connected to the computer through a concentratorthat wants to use flow control.You should first try to tell the concentrator not to use flow control.If you succeed in this, try making the terminal work withoutflow control, as described in the preceding section.If that line of approach is not successful, map some other charactersinto C-s and C-q using keyboard-translate-table. The example aboveshows how to do this with C-^ and C-\.* Control-S and Control-Q commands are ignored completely on a net connection.Some versions of rlogin (and possibly telnet) do not pass flowcontrol characters to the remote system to which they connect.On such systems, emacs on the remote system cannot disable flowcontrol on the local system.One way to cure this is to disable flow control on the local host(the one running rlogin, not the one running rlogind) using thestty command, before starting the rlogin process. On many systems,"stty start u stop u" will do this.Some versions of tcsh will prevent even this from working. One wayaround this is to start another shell before starting rlogin, andissue the stty command to disable flow control from that shell.* Screen is updated wrong, but only on one kind of terminal.This could mean that the termcap entry you are using for thatterminal is wrong, or it could mean that Emacs has a bug handingthe combination of features specified for that terminal.The first step in tracking this down is to record what charactersEmacs is sending to the terminal. Execute the Lisp expression(open-termscript "./emacs-script") to make Emacs write allterminal output into the file ~/emacs-script as well; then dowhat makes the screen update wrong, and look at the fileand decode the characters using the manual for the terminal.There are several possibilities:1) The characters sent are correct, according to the terminal manual.In this case, there is no obvious bug in Emacs, and most likely youneed more padding, or possibly the terminal manual is wrong.2) The characters sent are incorrect, due to an obscure aspect of the terminal behavior not described in an obvious way by termcap.This case is hard. It will be necessary to think of a way forEmacs to distinguish between terminals with this kind of behaviorand other terminals that behave subtly differently but areclassified the same by termcap; or else find an algorithm forEmacs to use that avoids the difference. Such changes must betested on many kinds of terminals.3) The termcap entry is wrong.See the file etc/TERMS for information on changesthat are known to be needed in commonly used termcap entriesfor certain terminals.4) The characters sent are incorrect, and clearly cannot be right for any terminal with the termcap entry you were using.This is unambiguously an Emacs bug, and can probably be fixedin termcap.c, tparam.c, term.c, scroll.c, cm.c or dispnew.c.* Output from Control-V is slow.On many bit-map terminals, scrolling operations are fairly slow.Often the termcap entry for the type of terminal in use failsto inform Emacs of this. The two lines at the bottom of the screenbefore a Control-V command are supposed to appear at the top afterthe Control-V command. If Emacs thinks scrolling the lines is fast,it will scroll them to the top of the screen.If scrolling is slow but Emacs thinks it is fast, the usual reason isthat the termcap entry for the terminal you are using does notspecify any padding time for the `al'and`dl' strings. Emacsconcludes that these operations take only as much time as it takes tosend the commands at whatever line speed you are using. You mustfix the termcap entry to specify, for the `al'and`dl', as muchtime as the operations really take.Currently Emacs thinks in terms of serial lines which send charactersat a fixed rate, so that any operation which takes time for theterminal to execute must also be padded. With bit-map terminalsoperated across networks, often the network provides some sort offlow control so that padding is never needed no matter how slowan operation is. You must still specify a padding time if you wantEmacs to realize that the operation takes a long time. This willcause padding characters to be sent unnecessarily, but they donot really cost much. They will be transmitted while the scrollingis happening and then discarded quickly by the terminal.Most bit-map terminals provide commands for inserting or deletingmultiple lines at once. Define the `AL'and`DL' strings in thetermcap entry to say how to do these things, and you will havefast output without wasted padding characters. These strings shouldeach contain a single %-spec saying how to send the number of linesto be scrolled. These %-specs are like those in the termcap`cm'string.Youshouldalsodefinethe`IC' and `DC'stringsifyourterminalhasacommandtoinsertordeletemultiplecharacters.Thesetakethenumberofpositionstoinsertordeleteasanargument.A`cs' string to set the scrolling region will reduce the amountof motion you see on the screen when part of the screen is scrolled.* Your Delete key sends a Backspace to the terminal, using an AIXterm.The solution is to include in your .Xdefaults the lines: *aixterm.Translations: #override <Key>BackSpace: string(0x7f) aixterm*ttyModes: erase ^?This makes your Backspace key send DEL (ASCII 127).* You type Control-H (Backspace) expecting to delete characters.Put `stty dec'inyour.loginfileandyourproblemswilldisappearafteradayortwo.ThechoiceofBackspaceforerasurewasbasedonconfusion,causedbythefactthatbackspacingcauseserasure(later,whenyoutypeanothercharacter)onmostdisplayterminals.Butitisamistake.Deletionoftextisnotthesamethingasbackspacingfollowedbyfailuretooverprint.Idonotwishtopropagatethisconfusionbyconformingtoit.Forthisreason,Ibelieve`sttydec' is the right mode to use,and I have designed Emacs to go with that. If there were a thousandother control characters, I would define Control-h to delete as well;but there are not very many other control characters, and I thinkthat providing the most mnemonic possible Help character is moreimportant than adapting to people who don'tuse`sttydec'.If you are obstinate about confusing buggy overprinting with deletion,you can redefine Backspace in your .emacs file: (global-set-key "\b" 'delete-backward-char)Youmaythenwishtoputthefunctionhelp-commandonsomeotherkey.Ileavetoyouthetaskofdecidingwhichkey.*EditingfilesthroughRFSgivesspurious"file has changed"warnings.ItispossiblethatachangeinEmacs18.37getsaroundthisproblem,butincasenot,hereisadescriptionofhowtofixtheRFSbugthatcausesit.Therewasaseriouspairofbugsinthehandlingofthefsync()systemcallintheRFSserver.Thefirstisthatthefsync()callishandledasanothernamefortheclose()systemcall(!!).Itappearsthatfsync()isnotusedbyverymanyprograms;Emacsversion18doesanfsync()beforeclosingfilestomakesurethatthebitsareonthedisk.ThisisfixedbytheenclosedpatchtotheRFSserver.Thesecond,moreseriousproblem,isthatfsync()istreatedasanon-blockingsystemcall(i.e.,it's implemented as a message that gets sent to the remote system without waiting for a reply). Fsync is a useful tool for building atomic file transactions. Implementing it as a non-blocking RPC call (when the local call blocks until the sync is done) is a bad idea; unfortunately, changing it will break the RFS protocol. No fix was supplied for this problem. (as always, your line numbers may vary) % rcsdiff -c -r1.2 serversyscall.c RCS file: RCS/serversyscall.c,v retrieving revision 1.2 diff -c -r1.2 serversyscall.c *** /tmp/,RCSt1003677 Wed Jan 28 15:15:02 1987 --- serversyscall.c Wed Jan 28 15:14:48 1987 *************** *** 163,169 **** /* * No return sent for close or fsync! */ ! if (syscall == RSYS_close || syscall == RSYS_fsync) proc->p_returnval = deallocate_fd(proc, msg->m_args[0]); else { --- 166,172 ---- /* * No return sent for close or fsync! */ ! if (syscall == RSYS_close) proc->p_returnval = deallocate_fd(proc, msg->m_args[0]); else {* Vax C compiler bugs affecting Emacs.You may get one of these problems compiling Emacs: foo.c line nnn: compiler error: no table entry for op STASG foo.c: fatal error in /lib/ccomThese are due to bugs in the C compiler; the code is valid C.Unfortunately, the bugs are unpredictable: the same constructmay compile properly or trigger one of these bugs, dependingon what else is in the source file being compiled. Even changesin header files that should not affect the file being compiledcan affect whether the bug happens. In addition, sometimes filesthat compile correctly on one machine get this bug on another machine.As a result, it is hard for me to make sure this bug will not affectyou. I have attempted to find and alter these constructs, but morecan always appear. However, I can tell you how to deal with it if itshould happen. The bug comes from having an indexed reference to anarray of Lisp_Objects, as an argument in a function call: Lisp_Object *args; ... ... foo (5, args[i], ...)...putting the argument into a temporary variable first, as in Lisp_Object *args; Lisp_Object tem; ... tem = args[i]; ... foo (r, tem, ...)...causes the problem to go away.The `contents'fieldofaLispvectorisanarrayofLisp_Objects,soyoumayseetheproblemhappeningwithindexedreferencestothat.*68000CcompilerproblemsVarious68000compilershavedifferentproblems.Thesearesomethathavebeenobserved.**Usingvalueofassignmentexpressiononuniontypeloses.Thismeansthatx=y=z;orfoo(x=z);doesnotworkifxisoftypeLisp_Object.**"cannot reclaim"error.Thismeansthatanexpressionistoocomplicated.Yougetthecorrectlinenumberintheerrormessage.Thecodemustberewrittenwithsimplerexpressions.**XCONS,XSTRING,etcmacrosproduceincorrectcode.Iftemacsfailstorunatall,thismaybethecause.Compilethistestprogramandlookattheassemblercode:structfoo{charx;unsignedinty:24;};lose(arg)structfooarg;{test((int*)arg.y);}Ifthecodeisincorrect,yourcompilerhasthisproblem.IntheXCONS,etc.,macrosinlisp.hyoumustreplace(a).u.valwith((a).u.val+coercedummy)wherecoercedummyisdeclaredasint.Thisproblemwillnothappenifthem-...hfileforyourtypeofmachinedefinesNO_UNION_TYPE.Thatistherecommendedsettingnow.*CcompilersloseonreturningunionsIhearthatsomeCcompilerscannothandlereturningauniontype.MostofthefunctionsinGNUEmacsreturntypeLisp_Object,whichisdefinedasauniononsomerarearchitectures.Thisproblemwillnothappenifthem-...hfileforyourtypeofmachinedefinesNO_UNION_TYPE.